Applicants claim, under 35 U.S.C. xc2xa7119, the benefit of priority of the filing date of Mar. 9, 2001 of a German patent application, copy attached, Serial Number 101 11 368.4, filed on the aforementioned date, the entire contents of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a torsion-proof, but radially resilient connection of a stator of an angle encoder with a stator of an object to be measured. The present invention further relates to an angle encoder having a stator and a shaft, a coupling and a spring element.
2. Discussion of Related Art
Angle encoders are used for determining the angular position, the angular speed or other angle-dependent values of a rotor of an object to be measured, in particular a motor, and for making them available for purposes of display, control of a machine tool, regulation or other evaluations.
For the compensation of alignment errors in the course of coupling the shaft of the angle encoder to the rotor, and therefore of radial deflections of the rotatable rotor, a coupling is arranged between the stator of the angle encoder and the stationary object to be measured, which connects the stator of the angle encoder in a torsion proof, but radially and preferably also axially resilient manner, with the stationary object to be measured.
Such an angle encoder is known, for example, from DE 195 21 845 C2.
In connection with the angle encoder in accordance with DE 196 29 585 A1 it was found that it is advantageous for certain applications to arrange the coupling between the stator and the stationary object to be measured in the area of the bearing device of the rotor. The installation space available in this area is very limited, so that problems in reaching and actuating the device for radial clamping of the coupling can arise in actual use.
An angle encoder with a coupling between the stator and the stationary object to be measured is furthermore described in DE 200 08 590 U1. The leaf spring arms of the coupling are crammed in place on the stationary object because of external pressure, or spring pressure because of a deformation of the coupling. The introduction of the clamping force takes place by an axial displacement of the angle encoder with respect to the stationary object to be measured, and the clamping force is directly proportional to the relative axial position of the two elements. Assembly is made more difficult because of this.
An object of the present invention is based on disclosing a coupling for an angle encoder that is easy to mount.
This object is attained by a coupling for the torsion-proof, but radially resilient connection of a stator of an angle encoder with a stator of an object to be measured, the coupling includes a spring element either normally in a first position but when the spring element is bent out by a bending force the spring element moves from the first position through a click point to a second position where the spring element engages a portion of the angle encoder or the spring element is normally biased in a first position but when the bias of the spring element at said first position is canceled the spring element is moved to a second position where the spring element engages a portion of the angle encoder.
It is a further object of the present invention to disclose an angle encoder having this coupling.
This further object is attained by an angle sensor that includes a first stator and a shaft for measuring an angular position between a second stator of an object to be measured and a rotor, which is rotated with respect to the second stator around an axis of rotation and a coupling for torsion-proof, but radially resilient connection of the first stator with the second stator. The coupling includes a spring element that is either normally in a first position but when the spring element is bent out by a bending force the spring element moves from the first position through a click point to a second position or the spring element normally biased in a first position but when the bias of the spring element at the first position is canceled the spring element is moved to a second position.
The advantages obtained by the present invention reside in particular in that the coupling can be installed in the vicinity of the bearing device of the rotor of the angle encoder, and that in spite of crowded installation conditions the coupling can be fastened to the stationary object solidly and fixed against relative rotation. A stable and space-saving mounting is possible. During mounting and operation, the force required for assured clamping does not act, at least not completely, on the angle encoder.
Further advantages, as well as details, of the present invention ensue from the following description of a preferred embodiment, making reference to the drawings.